Cleaner for surface coverings



July 9, 1940. R. E. DUNBAR CLEANER FOR SURFACE COVERING'S 2 Shets-Sheet1 Filed March 31, 1937 Inventor: Ralph E.Dunbar;

y 9, 1940. R. E. DUNBAR 2,207,582

CLEANER FOR SURFACE COVERINGS Filed March 31, 1937 2 Sheets-Sheet 2 lventomfz Ralph E. Dunbar,

Carney.

Patented July 9, 1940 UNITED STATES PATENT OFFICE Ralph E. Dunbar, EastCleveland, Ohio, assignor to Electric Vacuum Cleaner Company, Inc.,Cleveland, Ohio, a corporation of New York 1 Application March 31, 1937,Serial No. 134,052

1 Claim.

The present invention relates to brushes for floor coverings and thelike, and particularly to brushes which are suitable for use in vacuumcleaners or other cleaners for surface coverings and the like.

The object of my invention is to provide an improved brush of this typeand in particular to provide an improved brush construction in cleanersfor surface coverings.

In the accompanying drawings, Fig; 1 is a front elevation partly insection of a vacuum cleaner having a rotating brush embodying. myinvention, Fig. 2 is a sectional view takenthrough the center of thesuction nozzle at right angles to the length of the suction nozzle, Fig.3 is a sectional view showing the construction for rotatably supportingthe rotating brush, Fig. 4 is a fragmentary perspective view of thebrush element showing the manner of securing the bristles therein, Fig.5 is a fragmentary view showing the brush engaging a floor covering,Fig. 6 is a perspective view of a suctionnozzle equipped with a brushembodying my invention, Fig. '1 is a perspective view of the brushpartly broken away to show the manner of securing the bristles therein,and Fig. 8 is a fragmentary sectional view of the brush.

Referring to the drawings, I have shown my invention in connection witha vacuum cleaner having an outer casing I which is provided with asuction nozzle 2 and a discharge conduit 3. A suitable bag 4 forreceiving dirt is attached to the discharge conduit. A motor driven fanwithin the casing creates a suction at the 'nozzle which draws dirt fromthe surface being cleaned through the suction nozzle and discharges thedirt through the discharge conduit 3 and-into the bag 4. A handle 5 isprovided at the rear of the'casing. The cleaner is supported on frontsupporting wheels 6 and rear supporting wheels I. The elevation of thesuction nozzle with respect to. the surface being cleaned is adjusted bya member 8 having a suitable connection for raising and lowering oneofthe sets of wheels.-

The suction at the nozzle raises the floor covering or other materialbeing cleaned' against the bottom edges or lips 9 of the suction nozzle.

While held in this position the floor covering is subjected to abeatingand sweeping action by a rotatable agitating element or brush I0arranged in the suction nozzle. brush comprises two metal castings IIhaving cylindrical flanges I2 projecting from the adjacent ends whichextend inside a sleeve I3. The sleeve I3 forms a pulley by means ofwhich the The body of the agitating element is rotated by a belt I4passing over the motor shaft I5. The parts II are held in assembledrelation by a tube I6 having nuts II threaded on the ends thereof whichcooperate with inwardly extending flanges I8 to clamp the parts I Itogether. A suitable sealing washer I9 is placed between the nuts I! andthe flanges I8. In the outer end of each of the parts I I is acylindrical recess I9a in which is secured the outer raceway of a ballbear- 10 ing. The inner raceway 2I of the ball bearing is clampedagainst a collar 22 on a shaft 23 by means of a screw 24 threaded intothe end of the shaft. The screw 24 also secures a guard 25 to the shaft23. A grease sealing washer 26 5 is arranged between the collar 22 andthe recess I9a and another grease sealing washer 21 is arranged betweena plug 26 threaded into the end of the casting and a flange 28a on theguard 25. These seals also, keep dust from the ball bearing. A steelretaining washer 27a holds the washer 21 in place.

The rotating brush is mounted in the suction nozzle by spring clips 29which grip the periphery of the guard 25. With this arrangement, the 25guard 25 and the shaft 23 are held stationary within the suction nozzleand the brush is rotatably supported on the shaft. The particularconstruction for supporting the brush within the suction nozzle is notimportant and the arrangement for carrying the clips 29 is thereforeshown diagrammatically in elevation at 30.

In the outer surface of the rotor are two dovetail grooves in whichspiral helically along the length of the rotor. These grooves holdstrips 32 of felt which project beyond the body of the rotor. The feltstrips are flexible so that they may be inserted by sliding lengthwiseinto the dovetailslots. If necessary, the portion of the felt stripswithin the slot may be provided with a metal backing 33 which reenforcesthe portion of the felt within the dovetail slot.

' In. the outer face of the felt strips 32 are sockets 34 in which aretufted bristles 35. In the manufacture of the brush, a thread 36 isextended through the body of the felt strip forming a loop whichprojects above the upper end of the socket 34. The bristles 35 are thenbent over the loop and pulled into the socket by drawing the threadtially flush with the felt. The sides of the socket exert a. lateralcompression on the bristles, holding the bristles in intimate contactand preventing any substantial flexing.

During the use of the cleaner, the floor coverin is drawn against thelips 9 of the suction nozzle, and the part of the floor covering betweenthe lips is bowed upwardly. As the brush rotates successive portions ofthe felt strips 32 strike the bowed portion of the floor covering andforce it downward in opposition to the air flow through the suctionnozzle thereby subjecting the floor covering to a seating and sweepingaction. The felt being a homogeneous material presents a relativelysmooth surface to the floor covering and therefore has no tendency todig into the nap of the floor covering. The felt, therefore, can bequite rigid without increasing the wear on the floor covering. Itsrigidity is particularly effective in producing a beating action on thefloor covering. As the felt strips are drawn across the floor covering,due to the rotation of the brush, the ends of the bristles 35 sweepacross the nap of the floor covering and remove any particles of dirtwhich are held therein. Since the bristles 35 are substantially flushwith the felt and are supported substantially throughout their wholelength the bristles are quite stifi. There is, however, no tendency forthe bristles to dig into the nap of the floor covering and the sweepingaction of the brushes therefore results in less wear than in theconventional rotating brush construction in which the bristles project arelatively great distance from the brush body. The present constructionprovides the brushing effect of stiff bristles without the increasedwear which usually results from the use of stiff bristles. The feltstrips are also somewhat effective in brushing particles of dirt fromthe nap of the floor covering. For example, the felt strips alone havebeen found to be effective in removing particles of lint. This action ofthe felt strips is due to the fibrous nature of the felt.

The operation of the rotating brush does not change materially with use.The felt being a homogeneous material wears evenly and the nature of thesurface presented to the floor covering remains the same. The felt wearsat a rate which is substantially the same or slightly greater than therate of wear of the bristles. The ends of the bristles therefore remainsubstantially flush with the outer surface of the felt at all times.Froma broad aspect it is not essential that the strips 32 be made offelt. Any material which wears at a rate equal to or somewhat greaterthan the rate of wear of the bristles would be satisfactory. Thematerials substituted for the felt need not be of a fibrous naturealthough such materials will pick up lint and are therefore desirable.In fact, if the maximum lift of the brush .is not important, the strips32 may be made of a material which wears at a rate substantially lessthan the rate of wear of the bristles.

In Figs. 6 to 8 inclusive my invention is shown applied to a suctionnozzle 31 having a swivel coupling 38 for connecting it to a suctionhose. The lips 39 of the suction nozzle are preferably bowed upward atthe center so that when the nozzle is used for cleaning a floorcovering, the portion of the floor covering between the ends of thenozzle will be raised from the floor against the,bowed portions of thelips. In the rear wall 40 is secured a brush which comprises a feltstrip 4| clamped between metal plates 42 and 43. The plate", which islonger than the plate 43, is secured to of the bristles.

the rear face of the wall 40. The felt strip 4| fits in an opening inthe wall 40, the abutting edges of the strip and opening being in tightenough engagement so that no air leaks therebetween.

The opening in the wall 40 extends upwardly therein from the plane ofthe lips and transvcrsely through the wall to provide a passage to theinterior of the nozzle extending transversely through the wall andbounded on the top and sides by the edges of the opening and open at thebottom. The plate 43 and the felt strip are substantially flush with theinner surface of the wall 40. The brush is therefore in eifect mountedin the rear wall'of the suction nozzle as distinguished fromconstructions in which the brush is attached to the rear face of thewall. In the lower edge of the -felt strip are sockets 44 in which tuftsof bristles 45 are secured by staples 46. The felt is compressed betweenthe plates 42 and 43 and the bristles are accordingly securely held inthe sockets by the staples. The lower edge of the felt strip projectsslightly below the lip 39 of the wall 40. The length of the bristles 45is such that the ends of the bristles project slightly beyond the felt.As in the previously described construction the bristles aresubstantially flush with the felt.

In the use of the suction nozzle the floor covering being cleaned isdrawn upward against the lips of the suction nozzle by the suctionwithin the nozzle. As the nozzle is moved across the floor covering, theportion of the floor covering beneath the ends of the bristles 45 issubjected to a brushing action which dislodges dirt held in the nap ofthe floor covering. Since the major portion of the length of thebristles is held against lateral movement by the Walls of the sockets44, the ends of the bristles are quite stiff. However, since thebristles are substantially flush with the surface of the felt, thebristles cannot dig into the nap and cause objectionable wear. Theincreased brushing effect of stiff bristles is therefore obtainedwithout a corresponding increase in wear. One advantage of thisconstruction is that the bristles are located in the position for mostefiective brushing action. Another advantage of the construction is thatthe brush causes no loss of suction. This is due in part to the factthat the edges of the felt strip are held tightly against the edges ofthe opening in the wall 40 of the suction nozzle and thereis,'therefore, no leakage around the edges of the felt. Also, since thebristles are substantially flush with the felt, the floor coveringbetween the bristles is held against the felt by the suction. This tendsto decrease the leakage ofair between the bristles. Due to its fibrousnature, the felt is also somewhat helpful in removing lint from the napof the floor covering. The felt wears down at a rate which is equal toor slightly greater than the rate of wear The surface presented to thefloor covering therefore remains substantially constant throughout thelife of the brush. From a broad aspect it is not necessary that thebristles be held in a strip of felt. It is merely desirable that thematerial in which the bristles are held be of one which will wear downat a rate equal to or slightly greater than the rate of wear of thebristles.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

In a cleaner for surface covering or the like, a suction nozzle havingwalls providing surface contacting lips, an opening in one of said wallsextending upward in said wall from the plane of the lips thereofandtransversely through the wall to provide a passage to the interior ofthe nozzle extending transversely through said wall and bounded on thetop and sides by the edges of said opening and open at the bottom, astrip of felt secured in said opening, the abutting edges of the feltand said opening being in sealing engage-

